ElectricPavlov

Hmmmmm....    are you saying the book is   3*25 = 75 cm thick?

75 cm / 859 p = .08731 cm per page    = 8.731 x 10^-2  cm thick

I will assume you got the answer correct.....now you can see the 'outliers'     20 and 229   and remove them and do the calculations without them...

   outliers are probably mis-charged  (I guess) ...or perhaps the 229 is a multi-room suite    ....who knows ?

x = sqrt(26) cos 140^o  = ..........

 y= sqrt (26) sin 140^o = ..........

3x^4-7x^3+2x^2-bx+1      put in '1' for 'x' to find  f(1)    and it has to = 1

3 (1⁴) - 7(1³) + 2 (1²) - b(1) + 1   = 1         I think you should be able to take it from here !  

*** edited ****     Thanx, Alan ! 

If you put TWO numbers evenly spaced  between 1/8 and 1/4   you will trisect the number line

   from 1/8 to 1/4   is   1/8     you need to add   1/3  of 1/8  to find the first point

                                  1/3 x 1/8 = 1/24

        1/8 + 1/24 =  3/24 + 1/24 = 4/24 = 1/6      (first point)

THEN you need to add 2/3 of 1/8 to    1/8 to find the second point

2/3 * 1/8 = 2/24                   2/24 + 1/8 = 2/24 + 3/24 = 5/24    (second point)

You have 16 numbers...... list them in increasing order

add them all      then divide the sum by 16 to find the MEAN  (= average)

the MEDIAN is the number in the MIDDLE of the list

   there really is no MIDDLE number....so take the TWO middle numbers, add them then divide by 2  to find the MEDIAN

The MODE is the number that occurs the most often in the list of numbers......  give it a try !

8 X 3 X 4

Let's saolve the system of equations

Multiply first equation by -2

-12x-8y=-14    and add to second equation

kx+8y =7

(-12+k)x = -7

x = -7 / (-12+k)          Thus when k = 12  this would not be a real number     (denominator would be ' 0 ' ) 

10 gallons to start with

adding 'x' gallons of water      final volume = 10 + x

.9 (10) = amount of vineger

.1(10) = amount of water

amount of vineger before and after water addition is constant

.9(10) = .6(10+x)  

9 = 6 + .6x

3 = .6x

x = 5 gallons of water to be added

1000 m / 150 min    x   1.5 min =   .........   m  

1 km = 1000 m

2.5 hr = 150 min

90 sec = 1.5 min